JPS6045619B2 - Perfluorovinyl ether and its production method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel perfluorovinyl ether and a method for producing the same.

CF2■CFα of the present invention.

CF■CF is a new compound and has two types of perfluorovinyl groups with different reactivities, so it is attracting attention as a compound that can effectively impart double bond side chains to fluoropolymers. The inventor is CF2■CFO (CF, ).

It has been found that a new CF2■CFOCF2CF■CF2 can be produced smoothly and advantageously by thermally decomposing C00Na at a relatively low temperature. The novel compound in the present invention is
-CF2CF■ It is a perfluorovinyl ether containing a CF2 group at the end, and since the vinyl ether group CF2=CF0- and the vinyl group -CF2CF■CF2 differ in their reactivity, it can be used as a copolymerization component of various polymers in the side chain. It is possible to introduce the perfluorinated double bond leaving behind.

Conventionally known symmetrical vinyl ethers such as CF2*CF0CF=CF2 cannot be introduced in this manner. Therefore, as a comonomer that provides a crosslinking site consisting of a double bond,
The compounds of this invention are very useful. Perfluoro-3-oxa1,5-hexadiene (CF2■CF
-0CF2CF=CF2) has a boiling point of 67.0℃/76
-H, a colorless and transparent liquid, and its structure was confirmed by elemental analysis, infrared absorption spectrum, gas chromatograph direct mass spectrometry, and ゛F nuclear magnetic resonance spectroscopy.

FaFXFx″Fal \.

De′ \, de′／ ＼ / ゛＼ jFb Italy (o.

Fb゛The F nucleus in the above structural formula is marked with the symbols (a) to (y), and the results of each analysis will be described.

[Elemental analysis]

Measurement results: F: 66.52%, C: 26.31% Calculated values: F: 66.65%, C: 26.34% [Gas chromatograph direct coupled mass spectrometry (GCMS)] Mass spectrum measurement results are shown below. Shown in the table.

[19F nuclear magnetic resonance spectroscopy] The chemical shifts of each 19F nucleus are shown below.

(CCI, F standard, C6D effort) The binding constant for F nucleus was as follows.

[Infrared absorption spectroscopy]

The attached drawing shows the infrared absorption spectrum.

The attribution of the infrared absorption spectrum is shown in the table below.

As shown in the table, CF2=CFOCF2CF=CF2 exhibits characteristic infrared absorption derived from the dosing process.

The novel compounds of the present invention have the formula CF2=CFOCF2CF2
It can be prepared by thermally decomposing the sodium salt of CF2COONa at a temperature of 230-400°C with a residence time of 0.1-3@.

It is important to use sodium salt as the raw material; the desired product cannot be obtained using other alkali metal salts, such as potassium salt. In addition, the thermal decomposition temperature is preferably 250 to 30
A relatively low temperature of about 0°C is used. At high temperatures, the proportion of unidentified high-boiling compounds in the production increases, and at too low temperatures, the thermal decomposition rate is very low.
In addition, the proportion of low-boiling byproducts (CF2=CF-CF=CF2, etc.) tends to increase. Furthermore, thermal decomposition at the above-mentioned temperature, between 0.1 and 3 C@), and with a residence time of 5 is important. If the residence time is too long, the allyl vinyl ether produced tends to react further and the yield tends to decrease. Generally, it is desirable to shorten the residence time when the temperature is high. O The raw material for the thermal decomposition reaction in the present invention is desirably thermally decomposed with a water content of 100 ppm or less.

If the thermal decomposition reaction is carried out in a state containing more water than this, CF2 contained in the product = CFOCF2CF2CF
The ratio of 2COF and CF2=CFOCF2CFHCF35 increases, and the target product CF2=CFOCF2CF=CF
The yield of 2 tends to decrease. In the thermal decomposition reaction, it is also possible to perform the decomposition reaction while heating the raw material as it is.

It is also possible to carry out the heating in the presence of an alkali metal salt such as NaF or NaCl which is stable within the temperature range of the present invention as a heat medium. Generally, it is desirable to carry out the thermal decomposition reaction in the presence of an alkali metal salt in order to improve heat conduction and to easily control residence time. Furthermore, as mentioned above, since this reaction is strongly influenced by moisture, it is important to thoroughly dehydrate and dry the alkali metal salt coexisting with the reaction. A common method for drying raw materials is to calcinate them at high temperatures, but this method cannot be applied because the sodium salt of the raw materials decomposes. Therefore, an effective method is to disperse the material in a solvent that is azeotropic with water, such as CCl4, and then distill off the solvent azeotropically with water. In the present invention, the raw material CF2 = CFOCF2CF2CF2COONa can be obtained by various means.

For example, CF2=CFOCF2-CF2CF2COOR
It is possible to synthesize an ester (R is an alkyl group) by hydrolyzing it with HCl or the like and then reacting it with NaOH. In this case, when the ester is directly hydrolyzed with NaOH, the perfluorovinyloxy group is also decomposed, resulting in perfluorofumaric acid=sodium salt. Also, CF2=CFO
It is also possible to react the acid fluoride CF2CF2CF2COF with an alcohol ROH to obtain the above ester, or to react the acid fluoride directly with Na2cO3.

Others, 1r. T1,0<15Na0H or Na2c
Due to the reaction of O3, 1 Naυ and 1 ■ T2 Na i ~ Shishi υ2
1Nd1. , above is synthesized, and then partially thermally decomposed to produce C
It is also possible to obtain F2=CFO-(CF2+-3C02Na).

The novel compound of the present invention has a reactive double bond in the polymer.
It is effective as a monomer for introducing CF2CF=CF2, especially as a vulcanization site of rubber.

In addition, homopolymers of this monomer or some secondary
Since the copolymer with the component contains a high concentration of -CF2CF=CF2 groups in the molecule, it can also be applied as a thermosetting resin if peroxide or the like is used. Furthermore, new properties can be imparted to copolymers containing this monomer through various reactions, such as radical grafting reactions with other monomers and reactions with nucleophilic reagents. Next, examples of the present invention will be described in more detail, but it goes without saying that the present invention is not limited by such explanations. Example In a 1e round bottom flask equipped with a stirrer and a reflux condenser, 200f of purified water, 800y of acetone. ．． CF2=CF
O(CF2)3C02CH361.2y (0.2 mol)
, 35% hydrochloric acid 21f (0.2 mol) was added, and the mixture was heated at 65°C.
Reflux for an hour.

After distilling off acetone from the reaction solution using an evaporator, the product was extracted with ether, and CF2=CFO-(
CF3'+-CO2H was obtained almost quantitatively (yield 5
8.2y). Obtained CF2=CFO(CF2)3C0
2H58.2f (a). 2 mol) with 10% NaO under stirring
After dropping 80y of H aqueous solution, when water is distilled off, CF2=
CFO(CF2)3C02Na generated 62.5V (
yield 100%). Add 30f of CCl4 to 60f of this Na salt.
In addition, using a rotary evaporator, heat at 120°C for 1
wr! Dry under reduced pressure with NHy for 3 hours. Similarly, NaCl5Of, which had been dried with CCl, was placed in a 300 ml round bottom flask equipped with a stirrer and heated to 280°C. 1 order Hy in this container
Under reduced pressure of CF2=CFO(CF2)3C02Na58.
A small amount of 4 g was dropped and a thermal decomposition reaction was carried out with a residence time of about 3 seconds. The product was collected in a trap connected to the reactor and cooled with methanol dry ice and liquid nitrogen. The amount of product was 17.1y. As a result of the analysis, the main components are CF2=CFOCF2CF=CF2, CF2
=, CFOCF2CFHCF3, CF2=CFO(CF
2) 3C0F, and the desired product (Bp・6TC/76
"HV" was 8.0y (yield 20%). The reaction temperature, residence time, heat medium, etc. were varied as shown in Table 1 below, and the results obtained are summarized in Table 1) below.

Claims (1)

[Claims] 1. Perfluorovinyl ether represented by the formula CF_2=CFOCF_2CF=CF_2. 2 Formula CF_2=CFOCF_2CF_2CF_2CO
Sodium salt of ONa is heated to 0.0
．． Pyrolyzed with a residence time of 1 to 30 seconds to form the formula CF_2=CF
A method for producing perfluorovinyl ether, which is characterized by producing a compound of O-CF_2CF=CF_2. 3 CF_2=CFOCF_2CF_2CF_2COO
The method according to claim 2, characterized in that, prior to thermal decomposition, Na is dried to a water content of 100 ppm or less by adding a solvent that is azeotropic with water.